高温高压下B_4C合成金刚石的研究

A STUDY ON THE DIAMOND SYNTHESIS BY B 4C UNDER HIGH TEMPERATURE AND HIGH PRESSURE

压力为５．７～６．０ＧＰａ及１３７０～１５００℃温度范围内，Ｂ４Ｃ在Ｎｉ７０Ｍｎ２５Ｃｏ５系统中，高压相变为金刚石。合成的金刚石为深黑色，含硼量大于１ｗｔ％。粒度为２０μｍ左右，晶形多为立方体与八面体的各种聚形。反应后的金属触媒中，存在Ｎｉ２Ｂ等硼化物；非金属残留物中，存在Ｂ１３Ｃ２等高硼碳化物。

Diamond was synthesized by using B 4C as the carbon source in the Ni 70 ·Mn 25 Co 5 B 4C system under 5.7～6.0GPa and 1370～1500℃.This is the first example using pure B 4C as the carbon source to synthesize diamonds,which is dark and contains more than 1wt% of boron.The synthesized diamond has a grain size of about 20μm,is mainly a combination of cubic and octahedral bodies.After reaction,Ni 2B compounds are found to exist in the metallic catalyst left,and B 13 C 2 compounds with rich boron in the non metallic remainders.